Answer:
2.35 x 10²⁴ atoms Al
Explanation:
Given 3.9 moles of aluminum (Al), determine number of aluminum atoms in that quantity of substance.
By definition a mole is the mass of substance containing one Avogadro's Number (N₀) of particles. That is, 1 mole = 1 N₀ = 6.023 x 10²³ particles*.
So, if 1 mole aluminum contains 6.023 x 10²³ atoms of aluminum then
3.9 moles Al = 3.9 moles Al x 6.023 x 10²³ atoms Al/mole Al = 2.35 x 10²⁴ atoms Al.
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*The complete equivalent relationship is ...
1 mole (atoms or compounds) = 6.023 x 10²³ atoms or molecules = 1 formula weight of the substance = 22.4 Liters (if in gas phase at STP conditions (0°C and 1atm pressure).
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Sure hope this is understandable ... if not, kick back a note. Doc
